Re: [Tracker] Roadmap for 0.12

[Adrien Bustany <abustany gnome org>]

On Thu, 28 Jul 2011 11:26:10 +0200, Philip Van Hoof wrote:
> On Wed, 2011-07-27 at 22:56 +0300, Adrien Bustany wrote:
> > Le Wed, 27 Jul 2011 10:24:17 +0100,
> > Martyn Russell <martyn lanedo com> a Ãcrit :
>
> > > â Deleting orphaned resources?
> > >    This is not straight forward to do and we decided though we 
> > want to
> > >    do it, we just don't have time. This is useful in cases where 
> > (for
> > >    example, you have artists in the database for music that no 
> > longer
> > >    exists. What's hard about this is knowing what can be cleaned 
> > up).
> >
> > Additionally, this can easily be moved to an external process 
> > without
> > too much overhead... What we have for contacts is Harmattan is a 
> > daemon
> > that exports a DBus interface. With this interface you can:
> > 1. Register a SPARQL query to delete orphaned resources, with a 
> > unique
> >    identifier
> > 2. Increase the "load" for the query
> >    The load is an arbitrary double, when it reaches 1 the cleanup 
> > query
> >    is ran by the daemon. For exemple, the qtcontacts-tracker backend
> >    registers a contacts cleanup query, and increases the load 
> > everytime
> >    you insert/delete a contact so that the cleanup query is ran 
> > every
> >    100 updates.
> > This is only one approach to the problem, which we chose because it 
> > was
> > good enough and not too intrusive. There are surely other solutions,
> > which might or not be better according to what your requirements 
> > are.
>
> Hmm, I think the solution should be agnostic about the SPARQL queries
> and shouldn't require registering.

Yes, the whole point of this solution is that it works with an
unmodified Tracker... The refcounting solution is indeed nicer, but was
not an option for Harmattan in our timeframe, and also has to be very
carefully specified to avoid surprising behaviours :)

<snip>